Boxster wont start - Help pls ? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

clivep078 · 10-02-2011, 07:23 AM

Really need and appreciate some advice. I have just bought my first Porsche a Boxster S 3.2 2002.

The initial issue was difficulty to start when Hot, but once it turned over a few times, it popped a bit, sometimes stalled, but on 2nd or 3rd hot turnover was ok and it never cut out whilst running.

Then the problem started to happen sometimes (not always) when it was cold.

The problem got worse until it started cutting out whilst driving and then I couldn't start at all now even when cold.

So obviously an intermittent fault - getting worse - initially when hot.

Now this bit may be a bad steer - but during all the the only code I got was P0134 which is bad o2 sensor so I replaced that. Turned the key and it fired !!! hey sorted...... er no !!! has now stopped again and wont start - so I think the o2 code may have been due to very bad fuel / air mix during turnover and no firing. And the initial start after install a lucky start. This does happen sporadically. When I removed the sensor I got a code to tell me this and once reinstalled the code cleared so happy this is installed ok. No OBD errors at present.

Now - lifted lid off engine and I can hear a high pitched tone - like the scream of a relay or solenoid when the coil is breaking down, whilst the car is sat with ignition on. occasionally I then get a chatter like a relay chattering when it has a loose connection or the coil is failing. This sounds as if it is coming from the throttle body area. Saying this when I push the accelerator I can hear the throttle move smoothly so I think fly by wire is ok?

Hence my conclusion is that there may be some actuator, solenoid or valve etc which is responsible for presetting throttle position which initially was failing when hot but is now failing most of the time. If I do get a lucky start, it tends to run for quite some time before giving me issue or cutting out. but if it does, its a hell to get going again.

Any experts on starting routing, throttle bodies etc

Help really appreciated?

Many Thanks

Clive

Dale_K · 10-03-2011, 07:03 AM

I've read some other posts about cars that don't start even though they're cranking well and a common thread seems to be the fuel pump. There is a test port on the right side fuel rail for verifying the fuel pressure.

Ghostrider 310 · 10-03-2011, 07:13 AM

Fuel or spark, might check the fuel filter, also sounds a bit like vapor lock regarding the activity when hot.

jcb986 · 10-03-2011, 10:19 AM

Also check your coil paks...they can crack and cause the same problem

clivep078 · 10-03-2011, 11:29 AM

Thanks all. Any ideas on the high pitched noise and sporadic chatter from throttle body area?

Ghostrider 310 · 10-03-2011, 12:17 PM

Quote:

Originally Posted by clivep078

Thanks all. Any ideas on the high pitched noise and sporadic chatter from throttle body area?

You might need a mass air flow sensor

clivep078 · 10-03-2011, 01:32 PM

I'm goin to give the MAF a clean but its not flagging any codes and I wouldn't expect the fault to be so on / off in symptoms if it was MAF - just general running crap all the time.
Hence I am thinking this noise is a faulty solenoid or pump around the throttle area, which may have a big impact on the car starting or not. If you think back to the old days !! when we had chokes - if the choke was set wrong, the car wouldnt start - equally if you pulled the chocke out whilst driving, it would die - and if the choke was out when hot it wouldn't start. Hence is there something that performs the function of a choke in the area of the throttle housing? This could also explain my o2 sensor code when I was chucking unburned air and fuel on to it !!

Jager · 10-03-2011, 05:16 PM

What do your plugs look like?

clivep078 · 10-04-2011, 10:01 AM

Well when it fires it is fine and performance is good so I suspect the plugs are ok.

This is more of a - either it starts - or more often it does not - and when it dosnt it does not fire at all or even try just turns over.

If it was plugs id expect a slow cough and splutter until it got going and then poor performance generally

But i'll take a look at the weekend !

clivep078 · 10-23-2011, 11:23 AM

This turned out to be a fuel pump relay. Initially only a hot start problem, then cold start problem, then no start !! No CEL for this fault !!

Northway sorted it - cheap part £10 - very reasonable labour, so I had a 48K service and brake fluid done as well etc so everything tip top. Had an advisory on the RMS slow leak - but hey - don't we all....

Clive